It is known in the art to affect the trajectory of a light signal by affecting the refractive index of a medium of the signal propagation by an electric field. This is used in electro-optical deflectors and modulators.
For example, U.S. Pat. No. 4,930,853 discloses an electrooptic deflector composed of a plate made of a material with a refractive index which can be modified by the application of an electrical field, whereinto a collimated optical beam can be injected in direction parallel to the electrodes deposited on a plate face. Said electrodes are parallel to one another, equally-spaced and separately connected to voltage sources apt to increase the refractive index in the material passing from an electrode to the next. The emerging optical beam is deflected in the direction wherein the refractive index increases.
However, conventional electro-optical modulators typically require high operating voltages and have a high response time.